New moon

related topics
{math, energy, light}
{day, year, event}
{god, call, give}
{country, population, people}
{group, member, jewish}
{church, century, christian}
{math, number, function}
{work, book, publish}
{food, make, wine}
{mi², represent, 1st}

In astronomical terminology, the new moon is the lunar phase that occurs when the Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore in conjunction with the Sun as seen from Earth. At this time, the dark (unilluminated) portion of the Moon faces almost directly toward Earth, so that the Moon is not visible to the naked eye.

The original meaning of the phrase new moon was the first visible crescent of the Moon, after conjunction with the Sun. This takes place over the western horizon in a brief period between sunset and moonset, and therefore the precise time and even the date of the appearance of the new moon by this definition will be influenced by the geographical location of the observer. The astronomical new moon, sometimes known as the dark moon to avoid confusion, occurs by definition at the moment of conjunction in ecliptic longitude with the Sun, when the Moon is invisible from the Earth. This moment is unique and does not depend on location, and under certain circumstances it is coincident with a solar eclipse.

The new moon in its original meaning of first crescent marks the beginning of the month in lunar calendars such as the Muslim calendar, and in lunisolar calendars such as the Hebrew calendar, Hindu calendars, and Buddhist calendar. But in the Chinese calendar the beginning of the month is marked by the dark moon.

On April 14, 2010, the new moon was photographed, producing what is claimed to be the first ever image at the exact moment of the start of the New Moon phase.[1]

Contents

Religious use

  • The Islamic calendar has retained an observational definition of the new moon, marking the new month when the first Crescent Moon is actually seen, and making it impossible to be certain in advance of when a specific month will begin (in particular, the exact date on which Ramadan will begin is not known in advance). In Saudi Arabia, if the weather is cloudy when the new moon is expected, observers are sent up in airplanes.[citation needed] In Pakistan, there is a "Central Ruet-e-Hilal Committee" consisting of Ulemas (Religious Scholars), which takes help from 150 Observatories of Pakistan Meteorological Department all over the country and announces the decision of sighting of new moon. In Iran a special committee receives observations of every new moon to determine the beginning of each month. This committee uses one hundred groups of observers.

Full article ▸

related documents
Lunar phase
International Atomic Time
Analemma
Optical depth
243 Ida
Classical Kuiper belt object
Radiation pressure
Plane wave
Polaris
Magnetar
Pendulum
Hoag's Object
Inclination
Positronium
Super-Kamiokande
Electromagnetic force
Azimuth
Intensity (physics)
Aldebaran
Dioptre
Quantum Hall effect
Apsis
Sidereal year
Celestial coordinate system
Spectrum
Nemesis (star)
Right ascension
Theory of relativity
Astronomical unit
Planetary ring